3 replies to this topic

[daniel_johno]

Was just looking at a pink mini a mate is selling for my girlfriend. Head gasket was blown so i pulled the head off and the pistons have 21251 +30 (also id6 w08) stamped on them. With a ruler the bore measures roughly 72mm. Anyone had a +30 over bore? ive never heard of them before i thought it was just +20, 40 and 60.

What bore size would this give? im roughly thinking about 1305cc.

Thanks

Daniel

[8portdave]

Yeh that is quite normal mate the sizes go +10 +20 +30 +40 +60 i think its something like a 1307cc or there aouts +40 is 1310cc

[dklawson]

This topic also came up recently on the MiniMania/MiniSpares web site. I hadn't heard of +010, +030, etc but it was confirmed there that there was a time when this was common. I think today that it's much more common to find +020, +040, etc. like you said.

[Toady]

yes, my old mini which made 110bhp was overbored to +30thou. It made it a 1302cc iirc, that was about 7 years ago now!